A first embodiment of the present invention relates to a magnetic weight-bearing prosthetic socket system for coupling a prosthesis to an artificial limb. In this first embodiment, the system has two opposing magnetic fixtures repelling each other: one implanted at the point of amputation of a bone, and a second incorporated into the prosthesis. In a second embodiment of the present invention opposing magnetic fixtures are implanted into adjacent bone surfaces on either side of an articulating joint. The magnetic fixtures are oriented to repel each other and thus hold the bones apart. In a third embodiment, the magnetic fixtures are positioned in pairs on either side of an articulating joint to reduce lateral movement of the joint.
Artificial joints using magnetism to connect two opposing parts are known. For examples see U.S. Pat. No. 4,332,037 to Esformes et al., Italian patent 514,679 to Rosa, or German patent 320,756 to Heegewaldt. These patents all illustrate the use of the attractive force of magnets to hold a joint in place so that the artificial joint can move in a somewhat normal manner.
It is also true that artificial joints using the repulsive properties of magnets are known. For example, see U.S. Pat. No. 4,024,588 to Janssen et al. However, the illustrated device requires repelling magnets to operate within a cooperatively shaped magnetic socket for the device to work. Soft tissue covering a remnant bone can not be accommodated. The implantation requires that the end of each bone entering the joint be destroyed in order to effect the implantation. The magnets are positioned in a ball and socket relationship.
A need exists for a socket system which can be used to couple a prosthesis to an amputated limb. The socket system should be capable of transferring weight directly between the bone structure and the associated prosthesis without causing pain or discomfort to the person wearing the prosthesis. A first embodiment of this invention has as an object a requirement to transfer weight directly to a remnant bone so that any soft tissue covering the remnant bone will not be rubbed and irritated as the device is being used.
A need also exists for a magnetic system which can be used with an existing but damaged articulating joint to comfortably hold the bones of the joint apart. As the bones rotate in the articulating joint, a repelling force is needed which will keep the bones separated and reduce the friction associated with the rotation of the bones relative to one another. The structure should be capable of being inserted into ends of the bones forming the joint, but at the same time conserve and preserve the preexisting contour of the recipient bones.
A need also exists for a magnetic system which can be used with an existing but damaged articulating joint to comfortably hold the bones of the joint apart and at the same time reduce lateral movement of the joint.